A174913 Lesser of twin primes p1 and p2 such that 2*p1+p2 is a prime number.

3, 5, 17, 29, 59, 149, 197, 227, 239, 269, 419, 569, 659, 1277, 1427, 1487, 1667, 1949, 2087, 2129, 2267, 2339, 2549, 2789, 2999, 3359, 3389, 3929, 4049, 4157, 4217, 4229, 4517, 4637, 5099, 5417, 5477, 6089, 6197, 6299, 6359, 6569, 6659, 6827, 6959, 7127

Offset: 1

Author

Vladimir Joseph Stephan Orlovsky, Apr 02 2010

Keywords

• nonn

Comments

(p1, p2=p1+2) is a pair of twin primes.

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A001359

Programs

Mathematica

lst={};Do[p1=Prime[n];p2=p1+2;If[PrimeQ[p2]&&PrimeQ[2*p1+p2],AppendTo[lst,p1]],{n,7!}];lst
Transpose[Select[Partition[Prime[Range[1000]],2,1],#[[2]]-#[[1]] == 2 && PrimeQ[ 2#[[1]]+ #[[2]]]&]][[1]] (* Harvey P. Dale, Apr 09 2012 *)

Extensions

Definition edited by Harvey P. Dale, Aug 13 2024